The lens you choose will depend a lot on what kind of wildlife you want to photograph. Personally I mainly shoot small birds, so bigger reach is often an important factor. My first super-telephoto lens was the Sigma 150-600mm C which was a good starter piece of kit. However I found over time that the images were pretty soft on the 600mm end, so I upgraded to the Canon 500mm f/4 mark II super-telephoto prime lens. This has been my primary lens for the last 2 years and I love it. I often shoot with a 1.4x extender attached for added reach, which has worked very well without compromising image quality. This lens has also dropped considerably in price compared to other telephoto primes on the market.
For a long time I used to shoot handheld which was manageable despite the heavier 500mm prime lens. However, when I actually found a cooperative bird that stayed in one place for a while, my arm would tire before the bird flew away. This tends to be the exception but it quickly became a very annoying exception. For that reason, I now shoot almost exclusively using a monopod and side mount gimbal. I bought (and quickly sold) the Wimberley Monogimbal because it was too off-balance, but I settled on the Tomahawk GT2 by ProMediaGear which I have found to be outstanding. It allows me to hike very comfortably for longer distances while carrying my camera and lens over my shoulder while mounted to the gimbal head. When shooting from a hide or in a fixed position, I will use a regular tripod and full gimbal head for greater control and balance.
Last year I made the leap to Canon’s flagship DSLR, the 1DX III. Why didn’t you buy a mirrorless camera, I hear you ask? While I am excited by the future of mirrorless cameras, they are still in their infancy and have several limitations, such as poor battery life and focusing problems. The 1DX III has an amazing 16 frames per second which is invaluable when capturing those decisive moments in between heartbeats, especially when photographing small birds that move very quickly, even in micro-movements. The camera is only 21 megapixels which provides an unlimited buffer (no more missed shots!) and forces me to improve my fieldcraft and get closer to the subject because of the sacrificed crop-ability.
I use a dedicated camera rucksack made by f-stop. Their bags do not scream “I’m a camera bag” which is ideal for avoiding unwanted attention. I went for the Tilopa 50L model which fits my 1DX with attached 500mm prime. This model is just within the cabin baggage size limit for most international flights. In terms of comfort, I have never found a more ergonomic rucksack. The f-stop bags are so well designed that I can walk around comfortably for an entire day without getting a sore neck! The bag has straps on the side for attaching a tripod or monopod, and additional pockets on top for carrying gloves, lunch or other accessories.
Dressing in layers is important when shooting in the colder months, especially when arriving at a location before sunrise as the temperature can be substantially colder than a few hours later in the day. As a photographer perhaps one of the most important parts of your body to keep warm are your hands, so I use a pair of gloves by Valleret called the Markhof Pro V3. They have excellent grip and both thumb and pointer fingers have finger caps that flip back with magnets to give you access to your camera dials.
Super-telephoto prime lens: Canon EF 500mm F/4L IS II USM
Monopod: Gitzo GM4562
Monopod side-mount gimbal: ProMediaGear Tomahawk GT2
Tripod: Gitzo GT4553S Systematic
Tripod gimbal head: ProMediaGear Katana Pro Jr
Carry strap: BlackRapid Sport X QD Sling
Lens protection: Tragopan CamShield
RSPB Avocet Jacket by Country Innovation